I am an Indian planning to visit Peru. I'm looking at countries that I could transit through that won't require a tranist visa. Will I require a transit visa if I go through Brazil?
On the site of the Embassy of Brazil in New Delhi:
Travelers transiting through Brazilian airports to other countries, whenever the onward flight is booked under a separate ticket and/or different code.
Therefore, you need a visa to transit through Brazil in case you buy two plane tickets for any one-way journey (i. e. one from India to Brazil and one from Brazil to Peru).
Fortunately, most chances are you can buy a single ticket, which may include flight transfers and even travels with different carriers (but usually carriers have agreements for such cases, so that you can travel with several carriers on only one plane ticket). In this case, you won't be needing a transit visa.
The difference between buying one ticket and buying several tickets lies in the fact that if you buy a ticket including a transfer, once you land in the intermediary country (here, Brazil), you will probably stay in the boarding area of the airport and leave right onto your next flight and not even cross the border to enter Brazil, whereas buying two separate tickets will have you go through the border with Brazil, check-in for your second flight, and so on.